Abstract | Bračka skuta tradicionalni je hrvatski albuminski sir, bijele boje te mekane i kremaste konzistencije, a proizvodi se od ovčje sirutke koja zaostaje nakon tehnološkog procesa proizvodnje bračkog sira. Skuta ima visoku prehrambenu vrijednost zahvaljujući bogatom sadržaju sirutkinih proteina koji su lako probavljivi te imaju visok stupanj iskorištenja u organizmu.
Proces proizvodnje bračke skute nije standardiziran što utječe na iskoristivost proteina i masti, randman te teksturu skute. Iako temperatura zagrijavanja i pH vrijednost utječu na sposobnost agregacije proteina sirutke, najveća varijabilnost u procesu proizvodnje bračke skute uočena je za vrijeme trajanja zagrijavanja sirutke. Stoga je cilj ovog rada bio ispitati utjecaj trajanja zagrijavanja sirutke na teksturu bračke skute te iskoristivost masti i proteina odnosno randman u proizvodnji bračke skute.
Istraživanje je provedeno na 16 šarži bračke skute, proizvedenih s različitim vremenskim trajanjem zagrijavanja sirutke na dva obiteljska poljoprivredna gospodarstva s otoka Brača. Fizikalno-kemijske analize sirutke i bračke skute uključivale su određivanje pH-vrijednosti, udjela suhe tvari, suhe tvari bez masti, mliječne masti, proteina i laktoze. Računski su određeni iskoristivost masti i proteina u proizvodnji skute te stvarni randman, dok je tekstura sira određena testom kompresije.
Rezultati su pokazali da je vremensko trajanje zagrijavanja sirutke značajno utjecalo na fizikalno-kemijska svojstva (P<0,05; P<0,01), teksturu (P<0,01) i randman (P<0,05) bračke skute. Naime, provedenim istraživanjem utvrđeno je da je najveća iskoristivost mliječne masti i proteina iz sirutke u skutu bila kada se sirutka za proizvodnju skute zagrijavala u trajanju između 28,10 – 41,00 minuta, dok su najveći randman i čvrstoća bračke skute postignuti zagrijavanjem sirutke u trajanju od 41,01 – 54,00 minuta. Vremensko trajanje zagrijavanja sirutke duže od 54,00 minute negativno se odrazilo na navedena svojstva. |
Abstract (english) | Bračka skuta albumin cheese is a Croatian traditional whey cheese. It is white coloured cheese with soft and creamy texture, which is produced from sweet ovine whey that remains after removal of the curd during the production of Brač cheese. Skuta albumin cheese has a high nutritional value, which is the result of a rich content of proteins that are easy to digest and have high level of utilization in human body.
The process of Bračka skuta albumin cheese production is not standardized which could influence the recovery of milk fat and protein, cheese yield and texture of Bračka skuta. Although heating temperature and pH value have influence on whey protein aggregation, a duration of whey heating is the most variable factor. Therefore, the aim of this study was to examine the impact of whey heating time on the texture of Bračka skuta as well as on the recovery of milk fat and protein and on the cheese yield in the Bračka skuta albumin cheese production.
Research was conducted on 16 batches of Bračka skuta albumin cheese which were manufactured at two small-scale dairy farms located on the island of Brač. The heating time of whey in the production was different. Physicochemical analyses of whey and whey cheese included determination of pH-value, total solids, non-fat solids, fat, protein and lactose content. The cheese yield, milk fat and protein recovery were calculated using the formulas, while the cheese texture was determined by a compression test.
Based on the research results, it can be concluded that the whey heating time significantly affected physicochemical properties (P<0.05, P<0.01), texture (P<0.01) and cheese yield (P<0.05) of Bračka skuta albumin cheese. The highest milk fat and protein recovery to Bračka skuta albumin cheese was determined for the whey heating time between 28.10 – 41.00 minutes. The highest cheese yield and texture of Bračka skuta were determined for the whey heating time 41.01 – 54.00 minutes. Whey heating longer than a 54.00 minutes negatively affected the above mentioned properties. |